No, they did review them, but you didn't read the article. The excluded studies were either investigated something else, not common cold, or were so bad that they failed right away. They still gave short summaries of them, and gave the reasons for exclusion:
> Andrianova 2003: The definition of ARD included influenza, thus excluding it from our review.
> Rafinski 1974: We excluded this study because there was no comparison group and it was a non‐randomised controlled trial.
> Ushirotake 2004: As the study was not randomised or blinded, there is a high risk of bias.
> Hiltunen 2007: This study did not meet this criterion as the cellulose could not be considered a standard treatment or a placebo.
[...]
I won't copy all of them, please go and read it yourself!
If it's not a randomized, controlled, blinded trial then it's not a trial to be considered any further, their results are unreliable.